The inventors business involves machining large blocks of graphite into smaller precision shapes and sizes (commonly referred to as blanks) per an individual customer's specification. The largest portion of this business is the creation of rectangular blank shapes for electrical discharge machining (EDM). EDM is typically used within machine shops for the manufacture of hardened steel molds or dies that require intricate details.
The one piece graphite blank is an industry standard for EDM (electrical discharge machining) applications. It is highly reliable and relatively easy to machine into the desired shape for the EDM process. The standard one-piece electrode blank consists of a fixture holding area used to secure the electrode within the machine. The remaining area is used to contact the workpiece for the EDM or arcing/burning away of the workpiece material. However, the standard one-piece electrode is not an efficient use of material in many instances. When high cost material is required for the EDM process and the graphite used in the attachment area does not require the same, an inefficiency of material usage is created.
The dense high cost graphite material required for the arcing/burning of the work piece is not necessary for the graphite used for the fixture work holding area. Low cost graphite material can be used in this area. Thus, the one-piece electrode is inefficient use of material.